Abstract

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Background: B-Cell lymphoma/leukemia 2 (BCL2) and p53 involve in growth control and the apoptosis pathways, which appear to play a key role in tumor progression and prognosis. We analyzed the prognostic and predictive significance of BCL2 and p53 expression in estrogen receptor(ER)-positive breast cancer. Methods: We retrieved the data of 3,186 patients who were newly diagnosed with malignant breast cancer between August 2006 and December 2013. We analyzed BCL2/p53 index representing the relative expression of each protein and assessed its association with recurrence free survival(RFS), breast cancer-specific survival(BCSS), and overall survival(OS). Results A total of 511(60.2%) cases of ER-positive breast cancer showed BCL2-positive/p53-negative expression. 97 (11.4%) were BCL2-positive/p53-positive expression, 169(19.9%) were BCL2-negative/p53-negative expression, and 72(8.5%) were BCL2-negative/p53-positive expression. BCL2-positive/p53-negative expression showed an associated with favorable prognostic factors, such as well histological grade (p<0.001), no lymphovascular invasion (p=0.004), lower pathologic stage(p=0.033), progesterone receptor(PR)-positive (p<0.001), HER2 negative (p<0.001), lower Ki-67 level (<14%; p<0.001), and EGFR negative (p=0.001). BCL2/p53 expression showed a significant association with BCSS and OS in ER-positive breast cancer (p=0.002 and p=0.026, respectively). BCL2-positive/p53-negative and BCL2-positive/p53-positive breast cancer showed similar clinical prognostic course in recurrence and survival. In multivariate analysis, lymph node metastasis and BCL2-positive expression were independent prognostic factors for BCSS and OS. However, there was no correlation between BCL2/p53 expression and RFS. Conclusion: BCL2/p53 expression could be a predictor of BCSS and OS in ER-positive breast cancer.